1. Field of the Invention
The present invention relates to a method of prolonging the operative life of an imperforate endless metallic band of the type used in casting machines which produce a continuously cast metal product by molding molten metal between a continuous band and a cooperating groove of a rotary casting wheel.
2. General Background
In continuous casting machines of the rotary mold and belt type, the endless band is periodically in contact with molten metal at its pouring point and as it quickly cools. As a result, the band experiences severe thermal stresses. One of the major reasons for stopping the casting is the failure of some components, mainly this band, which sustain high thermal stress. The stresses are normally applied in a longitudinal zone of the band. Thermal stresses due to the hot metal on one side and cooling on the other side of the band cause cracks to appear in this longitudinal zone. After the cracks have appeared, the cooling fluid and/or the molten metal can seep through the cracks whereupon the casting operation must be ceased. Thus, it is of great importance to attempt to increase the life of the band as much as is possible so that the casting operation can be continuous for a maximum period of time.
3. Prior Art
Several techniques have been suggested to increase the life of the band, such as increasing its length and putting a protective coating on the band. These methods can be used separately or together.
Examples of prior art casting machines teaching various improvements are disclosed in the following table:
______________________________________ PRIOR ART PATENTS U.S. PAT. NO. INVENTOR(S) ISSUE DATE ______________________________________ 3,318,364 T. L. Bray et al. May 9, 1967 3,318,367 T. L. Bray May 9, 1967 3,336,972 D. B. Cofer et al. Aug. 22, 1967 3,811,492 G. C. Ward May 21, 1974 ______________________________________
The foregoing prior art patents are all assigned to Southwire Company, the assignee of the present application.